This is what I currently do with non-specialized services that require Docker. I have one container, which runs Docker Engine, and I throw everything on there, and then if I have a specialized container that needs Docker, I will still run its own CT. But then I use Docker Agent, So I can use one administration panel.
It's just annoying because I would rather just remove Docker from the situation because when you're running Proxmox, you're essentially running a virtualized system in a virtualized system because you have Proxmox, which is the bare bones running a virtualized environment for the container, which is then running a virtualized environment for the Docker container.